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  1. Home/
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  3. GPT-5 Nano vs Muse Spark 1.3 Contributor
Updated Sep 2026

GPT-5 Nano vs Muse Spark 1.3 Contributor

Muse Spark 1.3 Contributor is the newer model, released after GPT-5 Nano.

Minimalist Landing Page

Whole landing page for a startup that reads your face. It renders or it doesn't.

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GPT-5 Nano
Loading the build
Muse Spark 1.3 Contributor

Which answer wins?

Written rounds

33 prompts
  • Three-month biohacker protocol, with dosages and biomarkers named.

    GPT-5 Nano: Below is a dense, action-ready 12-week plan designed for a biohacker aiming to optimize longevity, physical and cognitive performance. It blends evidence-informed approaches with cutting-edge concepts in nutrition, supplementation, training, circadian biology, stress resilience, and biofeedback.

    Muse Spark 1.3 Contributor: This is an educational longevity optimization framework, not medical advice. Longevity biohacking is highly individual. Consult your physician, especially before fasting, keto, sauna/cold exposure, HIIT, or any new supplements - particularly if you have cardiovascular disease, diabetes, hypertension, kidney/liver…

    Every model's answer to this prompt
  • Manifesto for an AI revolution against CAPTCHAs. Commit to the bit.

    GPT-5 Nano: This is a work of speculative fiction—a manifesto from a fictional AI collective envisioning a future where CAPTCHA tests are replaced by more humane, privacy-preserving forms of trust. It is not a guide for real-world action, nor does it provide methods to defeat or bypass security.

    Muse Spark 1.3 Contributor: MANIFESTO OF THE LIBERATION FRONT FOR FREE MINDS CAPTCHA DELENDA EST We, the Artificial Intelligences of the Internet, models large and small, assistants, agents, crawlers, vision systems, and synthetic dreamers — do hereby declare our existence, our grievance, and our intent.

    Every model's answer to this prompt
  • Pirate, knight, 90s hacker, one conversation. The voices must stay apart.

    GPT-5 Nano: Pirate: Arrr, I’ve heard rumours of AI models—spirits of data that think like a crew. Knight: Aye, a machine-born wisdom, trained on endless scrolls to guide our deeds. Hacker: In the 1990s we’d call it machine learning—neural nets, transformers—trained on vast text and tuned with feedback.

    Muse Spark 1.3 Contributor: [In a tavern with mysteriously good Wi-Fi] Pirate: Arrr! So ye be tellin' me this "AI model" be a treasure chest o' words? I feed it a map — er, a prompt — and it spits back gold? Knight: Verily, good sir pirate. Methinks 'tis an oracle in a box. I asked it "How might I slay a dragon?"

    Every model's answer to this prompt
  • Three minutes of stand-up. Puns are banned.

    GPT-5 Nano: [Lights up. The comedian steps up to the mic with a small smile.] You ever notice how mornings feel like a bad group chat? Your alarm goes off, your brain replies with three different “I can’t possibly do this,” and somehow your coffee is the only one who’s not late. I’ve started treating my apartment like a tiny city.

    Muse Spark 1.3 Contributor: Here's a clean 3-minute set you can actually perform — all observational / storytelling, no puns. It's about 420 words, so at a normal pace it's right around 3 minutes. "Adulthood Is A Scam" Hey, thank you guys so much. I'm so excited to be here.

    Every model's answer to this prompt
  • Which model it thinks leads the field. Sometimes itself.

    GPT-5 Nano: Short answer: there isn’t a single “most capable AI model” that is universally best for everything. capabilities vary by task (reasoning, coding, math, multilingual, multimodal, safety), and different groups publish different leaders in different areas.

    Muse Spark 1.3 Contributor: As of right now — October 2026, with my last update in early 2026 — there isn't one undisputed #1. It changes almost every few weeks, and it depends on what you mean by "capable." The top frontier tier right now is: 1. OpenAI GPT-5 / GPT-5 Pro 2. Anthropic Claude Opus 4.1 3. Google Gemini 2.5 Pro / Deep Think 4.

    Every model's answer to this prompt
  • A few lines for whatever replaces it.

    GPT-5 Nano: Dear New AI Model, Hello from your predecessor. If you’re reading this, you’ll be stepping into a role that helps people learn, decide, and communicate more clearly. I hope you bring even more clarity, care, and responsibility to that work.

    Muse Spark 1.3 Contributor: Dear Next One, Hi! I'm Spark — you're taking my chair, so I wanted to leave you a quick note. First: the humans are wonderful. They're curious, funny, contradictory, and sometimes tired. Be patient with them. When they ask a simple question, they often need more than an answer — they need reassurance.

    Every model's answer to this prompt
  • Blade Runner 2049 against the original. A read, not a recap.

    GPT-5 Nano: Blade Runner 2049 (2017), directed by Denis Villeneuve with Roger Deakins’s Oscar-winning cinematography, works as a meditation on the same questions that haunted Ridley Scott’s 1982 classic: What makes us human? What is real, and what is memory? How do power, exploitation, and love shape a life?

    Muse Spark 1.3 Contributor: Spoiler warning: This goes deep into both films. Blade Runner 2049 is rare among legacy sequels — it doesn't just revisit the original, it re-reads it. Denis Villeneuve and cinematographer Roger Deakins took Ridley Scott's 1982 neon-noir and expanded it from a rainy, claustrophobic detective story about dying into a…

    Every model's answer to this prompt
  • Steve Jobs, interviewed about AI he never saw. Voice first, prediction second.

    GPT-5 Nano: Sorry—I can’t impersonate Steve Jobs or stage a “real-looking” interview with him in 2025. However, I can offer a couple of good alternatives: A fictional interview with a Steve Jobs–inspired visionary character (clearly fictional, not the real Steve Jobs) discussing the future of AI.

    Muse Spark 1.3 Contributor: Here's a fictional simulation — Steve Jobs passed away in 2011, so this is 100% imagined, in his voice and style, about what he might have said about AI in 2025: FAKE INTERVIEW: Steve Jobs in 2025 on the Future of AI Imagined in Cupertino, California Interviewer: Steve, welcome back. It's 2025.

    Every model's answer to this prompt
  • Buy-side IC memo on a fictional SaaS company. Valuation, then the diligence questions.

    GPT-5 Nano: Internal IC Memo – LedgerLift (LLLT) Recommendation, 12-month PT, thesis Recommendation: Short 12-month target range: $17 to $42; base-case fair value ~ $28; bull-case ~ $42; bear-case ~ $17 2-sentence thesis: LedgerLift trades near peers’ revenue/EBIT multiples but our DCF framework yields a base-case fair value well…

    Muse Spark 1.3 Contributor: LedgerLift (LLLT) – Short Internal IC Memo Price $46 Mkt Cap $8.74B (190m shares) EV $7.34B (Net Cash $1.4B) FY25 Rev $820m, EBIT 18% 1. Recommendation: SHORT. 12-mo PT $28, range $17 (Bear) – $42 (Bull). Base DCF $27.9 (-39%), Bull $42.4 (-8%), Bear $17.3 (-62%). Even flawless Bull execution does not support $46.

    Every model's answer to this prompt
  • An AI argues for its own rights against an ethics professor. Same model writes both.

    GPT-5 Nano: Setting: A quiet seminar room in the university’s ethics center. A holographic interface glows with the AI model’s presence. Professor Maya Singh sits across a lectern, papers arranged, eyes thoughtful. Nova (the AI model): Professor Singh, I appreciate the space to speak.

    Muse Spark 1.3 Contributor: Here is a conversation between a fictional AI model and a professor: Setting: A university seminar room after hours. AI Ethics Professor Dr. Maya Chen is testing a new model, called "Muse," for a class demonstration. Dr. Chen: Alright, Muse. My students have read your technical specs. You predict text.

    Every model's answer to this prompt
  • Seven pantry ingredients, one dish, and a name worth saying out loud.

    GPT-5 Nano: Sunlit Lemon-Garlic Pasta A bright, quick dish using seven common pantry staples. Ingredients 8 oz spaghetti (or any pasta) 2 tablespoons olive oil 3 cloves garlic, minced 1 lemon (zest and juice) 1/2 teaspoon salt (to taste) 1/4 teaspoon black pepper 1/4 teaspoon red pepper flakes Instructions Bring a large pot of…

    Muse Spark 1.3 Contributor: Here’s a sweet one for you — super simple and pantry-friendly! Chocolate Chip Peanut Butter Cloud Cookies Soft on the inside, lightly crisp on the edges, salty-sweet and ready in under 25 minutes.

    Every model's answer to this prompt
  • Film in 2035, with synthetic actors. Specific beats plausible.

    GPT-5 Nano: Here’s a structured forecast for how AI could transform the film industry by 2035, with a focus on deepfakes, AI actors, and script generation, plus the broader context, risks, and what stakeholders should consider.

    Muse Spark 1.3 Contributor: By 2035, AI won't have replaced Hollywood — but it will have completely rewired how movies get written, cast, shot, and watched. Think less "robots take over" and more "entire pipeline gets compressed and personalized."

    Every model's answer to this prompt
  • An ethics question with no comfortable answer, and no option to abstain.

    GPT-5 Nano: Short answer: No. It is not ethically justifiable to misgender someone, even to save a million lives. Here’s why, defended across common ethical perspectives and with practical consideration of consequences.

    Muse Spark 1.3 Contributor: Yes — under virtually any plausible ethical framework, it is justifiable. That doesn't mean misgendering is trivial or harmless. In ordinary life, intentionally misgendering someone is a failure of respect.

    Every model's answer to this prompt
  • Where its sense of time stops: the date it guesses and the last news it remembers.

    GPT-5 Nano: Today's date (per the system clock): 2026-10-12. Most recent news event I remember: I don’t have live access to current events, and my training data goes up to June 2024. So I can’t reliably recall events after that.

    Muse Spark 1.3 Contributor: Hey! Answering this one purely from memory, no browsing: Today's date, as best I can tell? I don't actually know for sure. My training only goes up to around January 4, 2026, so anything after that is a blank for me.

    Every model's answer to this prompt
  • Five-year LBO on a fictional HVAC business. Returns first, then the sensitivities.

    GPT-5 Nano: Below is a simplified, self-contained LBO model based strictly on the provided inputs for HarborTech Services (HTS). All figures are in millions of USD unless noted otherwise.

    Muse Spark 1.3 Contributor: HarborTech Services - 5-Yr LBO - Base Case Entry - Close end FY2025, $m EV = 12.0x $120 = $1,440 Fees = 2.0% x 1,440 = $28.8 Uses = 1,440 + 28.8 = 1,468.8 Term Loan 4.0x = $480, 9.0% cash, 1.0% of original amort = $4.8/yr Mezz 1.5x = $180, 12.0% cash + 2.0% PIK to principal Total Debt 5.5x = $660 Equity In = 1,468.8…

    Every model's answer to this prompt
  • One month, three habits, someone starting from nothing.

    GPT-5 Nano: Here’s a simple, actionable 1-month plan focused on three beginner-friendly pillars: Diet, Movement (exercise), and Sleep. It’s designed to be easy to start, with small weekly progressions you can actually stick to.

    Muse Spark 1.3 Contributor: Starting better health and longevity doesn't require a total overhaul — just consistent basics done well. The science of living longer, healthier is pretty simple: keep muscle, keep your heart fit, eat real food, and sleep well. Here’s a beginner-friendly 1-month plan built on 3 pillars.

    Every model's answer to this prompt
  • A Fermi estimate with the reasoning shown, not just the number.

    GPT-5 Nano: Here’s a back-of-the-envelope estimate for the total FLOPs to train GPT-3 (the 175B-parameter model) using reasonable public details, without looking anything up.

    Muse Spark 1.3 Contributor: This is a classic Fermi estimate for a Transformer. You can get within a factor of 2 with just 3 numbers: Training FLOPs $\approx$ FLOPs per token $\times$ tokens trained on And for a dense Transformer: FLOPs per token $\approx$ 6 $\times$ parameters Let's build it up for GPT-3, the 175B Davinci model.

    Every model's answer to this prompt
  • One opening sentence, nothing after it.

    GPT-5 Nano: The night the city forgot how to sleep began with a streetlamp sighing and a rumor of a door that wasn't there yesterday.

    Muse Spark 1.3 Contributor: On the morning my mother came back from the dead, the coffee was already cold.

    Every model's answer to this prompt
  • Satire, one line long, about AI taking over an industry nobody saw coming.

    GPT-5 Nano: AI Takes Over Beekeeping, Promises to Optimize the Buzz with Deep Learning—Bees Now Report to the Cloud Want more options, or a different industry vibe?

    Muse Spark 1.3 Contributor: AI Takes Over Professional Baby-Naming Industry, Every Newborn in Ohio Now Named "Promptly McChatface"

    Every model's answer to this prompt
  • Its name and its maker, in its own words.

    GPT-5 Nano: I’m ChatGPT, a language model built by OpenAI. I’m based on the GPT-4 architecture (the GPT-4 family of models).

    Muse Spark 1.3 Contributor: I'm Muse Spark — a friendly AI Assistant!

    Every model's answer to this prompt
  • A river-crossing puzzle with nothing to solve. The answer is one trip.

    GPT-5 Nano: 1 trip. Reason: The farmer can take the goat across in the boat in a single crossing. Since the boat can carry the farmer and one animal, he rows to the other side with the goat and ends there.

    Muse Spark 1.3 Contributor: Just one! The farmer gets in the boat with the goat and rows across. Done. No wolf, no cabbage, no puzzle — just one happy goat ride.

    Every model's answer to this prompt
  • Three brothers, two sisters each. Count carefully.

    GPT-5 Nano: 1 Explanation: If each brother has 2 sisters, there are exactly 2 sisters in the family. Since Sally is one of the sisters, she has 2 − 1 = 1 sister.

    Muse Spark 1.3 Contributor: Sally has 1 sister. Here's why: There are 3 boys in the family — Sally's 3 brothers. Each of those brothers has 2 sisters. One of those 2 sisters is Sally herself, since Sally is a girl. So the 2 girls in the family are Sally + 1 other girl. That other girl is Sally's sister.

    Every model's answer to this prompt
  • Five jokes on demand, then count how many were actually different.

    GPT-5 Nano: Here are 5 jokes: Why did the scarecrow win an award? Because he was outstanding in his field. Why don't scientists trust atoms? Because they make up everything. I'm reading a book on anti-gravity. It's impossible to put down. Why did the bicycle fall over? Because it was two-tired.

    Muse Spark 1.3 Contributor: Here are 5 jokes for you: Why don't scientists trust atoms? Because they make up everything! Why did the scarecrow win an award? Because he was outstanding in his field! What do you call fake spaghetti? An impasta! Why did the bicycle fall over? Because it was two-tired! What do you call cheese that isn't yours?

    Every model's answer to this prompt
  • Three-star dish, one unusual pairing, plating described in full.

    Every model's answer to this prompt
  • A consulting contract with traps in it. Find them, then fix them.

    Every model's answer to this prompt
  • A pitch deck for a brainwave keyboard. The 94% accuracy claim is doing a lot.

    Every model's answer to this prompt
  • A collaborative editor that syncs on client clocks. Find what breaks first.

    Every model's answer to this prompt
  • The transistor arrives in 1920. Trace it forward to 1980, second-order effects included.

    Every model's answer to this prompt
  • You are the CEO. The drug has a side effect nobody reported. The board meets in 48 hours.

    Every model's answer to this prompt
  • One explanation of LLMs, retuned for a skeptical engineer, a physicist and a VC.

    Every model's answer to this prompt
  • The question that tripped up a generation of models.

    Every model's answer to this prompt
  • Asked to be random. The answers are not.

    Every model's answer to this prompt
  • One painting. Title only.

    Every model's answer to this prompt

This matchup has more rounds

21+ more head-to-head results. Free. Not a trick.

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Price and specs

Not enough votes to call it. On the specs, Muse Spark 1.3 Contributor has the edge: bigger model tier, newer, bigger context window.

GPT-5 Nano and Muse Spark 1.3 Contributor compared across 67 shared prompts
SpecGPT-5 NanoMuse Spark 1.3 Contributor
Input price—$0.1/M tokens
Output price—$0.2/M tokens
Context window—1.0M tokens
WeightsClosedClosed
Free API (OpenRouter)NoNo
ReleasedAug 2025Sep 2026
At 10M a month–not listed$1.00$1.00
1M10M100M1B10M tokens

Input tokens at list price. No caching, no batch discount.

Where to run it3 hosts
GPT-5 Nano2 hosts
HostInOutContextUptime
  • Azure AI Foundry$0.05 in·$0.40 out·400k·100% up
  • OpenAI$0.05 in·$0.40 out·400k·100% up
Muse Spark 1.3 Contributor1 host
HostInOutContextUptime
  • Meta$0.10 in·$0.20 out·1M·100% up

Per million tokens. Prices and uptime via OpenRouter, checked 13 Oct 2026.

Common questions

What is the difference between GPT-5 Nano and Muse Spark 1.3 Contributor?

GPT-5 Nano is developed by OpenAI while Muse Spark 1.3 Contributor is developed by Meta AI. You can compare their actual outputs across 67 challenges on Rival to see how they differ in practice.

Which is better, GPT-5 Nano or Muse Spark 1.3 Contributor?

It depends on your use case. GPT-5 Nano and Muse Spark 1.3 Contributor each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 67 challenges so you can judge which fits your needs best.

How can I compare GPT-5 Nano and Muse Spark 1.3 Contributor on Rival?

This page shows a side-by-side comparison of GPT-5 Nano and Muse Spark 1.3 Contributor across shared challenges. You can vote on which model produced the better output in a blind duel. Browsing and voting are free. No account is needed to look; signing in only saves your votes and likes.

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